Make flags UI available on release build of launcher

The UI will only be shown on eng/userdebug platform builds.

Bug: 117223984
Change-Id: I27843f2d856a4a19f3fe53c4d306606eaa5714a2
diff --git a/src/com/android/launcher3/SettingsActivity.java b/src/com/android/launcher3/SettingsActivity.java
index 1f80226..60edcda 100644
--- a/src/com/android/launcher3/SettingsActivity.java
+++ b/src/com/android/launcher3/SettingsActivity.java
@@ -43,6 +43,7 @@
 import android.widget.Adapter;
 import android.widget.ListView;
 
+import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.graphics.IconShapeOverride;
 import com.android.launcher3.notification.NotificationListener;
 import com.android.launcher3.util.ListViewHighlighter;
@@ -57,6 +58,8 @@
 public class SettingsActivity extends Activity
         implements PreferenceFragment.OnPreferenceStartFragmentCallback {
 
+    private static final String FLAGS_PREFERENCE_KEY = "flag_toggler";
+
     private static final String ICON_BADGING_PREFERENCE_KEY = "pref_icon_badging";
     /** Hidden field Settings.Secure.NOTIFICATION_BADGING */
     public static final String NOTIFICATION_BADGING = "notification_badging";
@@ -126,6 +129,12 @@
             getPreferenceManager().setSharedPreferencesName(LauncherFiles.SHARED_PREFERENCES_KEY);
             addPreferencesFromResource(R.xml.launcher_preferences);
 
+            // Only show flag toggler UI if this build variant implements that.
+            Preference flagToggler = findPreference(FLAGS_PREFERENCE_KEY);
+            if (flagToggler != null && !FeatureFlags.showFlagTogglerUi()) {
+                getPreferenceScreen().removePreference(flagToggler);
+            }
+
             ContentResolver resolver = getActivity().getContentResolver();
 
             ButtonPreference iconBadgingPref =